Align Hibernate 5 join table names with those from SpringNamingStrategy

Previously, the name of a join table when using Hibernate 5 would
differ from those when using Hibernate 4 with the default
SpringNamingStrategy.

This commit introduces SpringImplicitNamingStrategy which customises the
name of join tables to match those produced by SpringNamingStrategy.

Closes gh-5880

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/orm/jpa/JpaProperties.java

@@ -235,6 +235,8 @@ public class JpaProperties {
 
 		private static final String DEFAULT_PHYSICAL_STRATEGY = "org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy";
 
+		private static final String DEFAULT_IMPLICIT_STRATEGY = "org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy";
+
 		/**
 		 * Hibernate 5 implicit naming strategy fully qualified name.
 		 */
@@ -288,7 +290,8 @@ public class JpaProperties {
 
 		private void applyHibernate5NamingStrategy(Map<String, String> properties) {
 			applyHibernate5NamingStrategy(properties,
-					"hibernate.implicit_naming_strategy", this.implicitStrategy, null);
+					"hibernate.implicit_naming_strategy", this.implicitStrategy,
+					DEFAULT_IMPLICIT_STRATEGY);
 			applyHibernate5NamingStrategy(properties,
 					"hibernate.physical_naming_strategy", this.physicalStrategy,
 					DEFAULT_PHYSICAL_STRATEGY);

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/orm/jpa/JpaPropertiesTests.java

@@ -26,6 +26,7 @@ import org.junit.After;
 import org.junit.Test;
 
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy;
 import org.springframework.boot.orm.jpa.hibernate.SpringNamingStrategy;
 import org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy;
 import org.springframework.boot.test.util.EnvironmentTestUtils;
@@ -98,11 +99,14 @@ public class JpaPropertiesTests {
 		JpaProperties properties = load(HibernateVersion.V5);
 		Map<String, String> hibernateProperties = properties
 				.getHibernateProperties(mockStandaloneDataSource());
-		assertThat(hibernateProperties).doesNotContainKeys(
-				"hibernate.ejb.naming_strategy", "hibernate.implicit_naming_strategy");
+		assertThat(hibernateProperties)
+				.doesNotContainKeys("hibernate.ejb.naming_strategy");
 		assertThat(hibernateProperties).containsEntry(
 				"hibernate.physical_naming_strategy",
 				SpringPhysicalNamingStrategy.class.getName());
+		assertThat(hibernateProperties).containsEntry(
+				"hibernate.implicit_naming_strategy",
+				SpringImplicitNamingStrategy.class.getName());
 	}
 
 	@Test

spring-boot-samples/spring-boot-sample-jpa/pom.xml

@@ -28,8 +28,8 @@
 			<artifactId>hibernate-entitymanager</artifactId>
 		</dependency>
 		<dependency>
-			<groupId>org.hsqldb</groupId>
-			<artifactId>hsqldb</artifactId>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
 			<scope>runtime</scope>
 		</dependency>
 		<dependency>

spring-boot-samples/spring-boot-sample-jpa/src/main/resources/import.sql

@@ -7,11 +7,11 @@ insert into note(title, body) values ('Spring Framework', 'Core support for depe
 insert into note(title, body) values ('Spring Integration', 'Extends the Spring programming model to support the well-known Enterprise Integration Patterns.')
 insert into note(title, body) values ('Tomcat', 'Apache Tomcat is an open source software implementation of the Java Servlet and JavaServer Pages technologies.')
 
-insert into note_tag(notes_id, tags_id) values (1, 1)
-insert into note_tag(notes_id, tags_id) values (2, 1)
-insert into note_tag(notes_id, tags_id) values (3, 1)
-insert into note_tag(notes_id, tags_id) values (1, 3)
-insert into note_tag(notes_id, tags_id) values (2, 3)
-insert into note_tag(notes_id, tags_id) values (3, 3)
-insert into note_tag(notes_id, tags_id) values (4, 2)
-insert into note_tag(notes_id, tags_id) values (4, 3)
+insert into note_tags(notes_id, tags_id) values (1, 1)
+insert into note_tags(notes_id, tags_id) values (2, 1)
+insert into note_tags(notes_id, tags_id) values (3, 1)
+insert into note_tags(notes_id, tags_id) values (1, 3)
+insert into note_tags(notes_id, tags_id) values (2, 3)
+insert into note_tags(notes_id, tags_id) values (3, 3)
+insert into note_tags(notes_id, tags_id) values (4, 2)
+insert into note_tags(notes_id, tags_id) values (4, 3)

spring-boot/src/main/java/org/springframework/boot/orm/jpa/hibernate/SpringImplicitNamingStrategy.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2012-2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.orm.jpa.hibernate;
+
+import org.hibernate.boot.model.naming.Identifier;
+import org.hibernate.boot.model.naming.ImplicitJoinTableNameSource;
+import org.hibernate.boot.model.naming.ImplicitNamingStrategy;
+import org.hibernate.boot.model.naming.ImplicitNamingStrategyJpaCompliantImpl;
+
+/**
+ * Hibernate {@link ImplicitNamingStrategy} that follows Spring recommended naming
+ * conventions. Naming conventions implemented here are identical to
+ * {@link ImplicitNamingStrategyJpaCompliantImpl} with the exception that join table names
+ * are of the form
+ * <code>{owning_physical_table_name}_{association_owning_property_name}</code>.
+ *
+ * @author Andy Wilkinson
+ * @since 1.4.0
+ */
+public class SpringImplicitNamingStrategy extends ImplicitNamingStrategyJpaCompliantImpl {
+
+	@Override
+	public Identifier determineJoinTableName(ImplicitJoinTableNameSource source) {
+		String name = source.getOwningPhysicalTableName() + "_"
+				+ source.getAssociationOwningAttributePath().getProperty();
+		return toIdentifier(name, source.getBuildingContext());
+	}
+
+}